Six people were killed in traffic accidents investigated by the Alabama State Troopers during the Labor Day weekend, authorities said today.

The official weekend period started at 6 p.m. Friday and continued through midnight Monday. Trooper spokesman Sgt. Steve Jarrett said the fatal crashes happened in Jefferson, Coffee, Butler, Mobile, Cherokee and Marengo counties.

Alcohol was involved in at least three of accidents, Jarrett said. The fatalities included one person on a motorcycle, a pedestrian, and an ATV rider. Of the remaining three vehicle crashes, none of the victims were wearing seatbelts.

Jarrett said a total 12 people were killed in traffic crashes over Labor Day weekend in 2011. Five of those crashes were investigated by the troopers.

Jarrett said it isn't immediately known how many additional fatalities were investigated this past weekend by other police agencies but haven't yet been reported to the state.